I'm not sure if the DH mechanism is that big a win. <br><br>If the claimed ID is an https:// URL, then the discovery will involve an SSL key exchange. <br><br>If the identity provider endpoint is on the same server, then the session created in the discovery process will almost certainly still be valid.
<br>If that key is valid, then relying on transport level encryption will avoid the additional PKOPs. <br><br>If the session is expired, or if the endpoint is on a separate host then establishing an SSL connection will involve some PKOPs; any DH PKOPs will still be superfluous.
<br><br>Why not rely on the transport layer to cover the key exchange ? <br><br>Simon<br><br><br><br><br>